Apparatus and method for preventing wind-up on rolls



P. E. DU 8015 July 7, 1964 APPARATUS AND METHOD FOR PREVENTING WIND-UP ON ROLLS 5 6 7 S W 1 m S UWfi m P E m M m I J Wm L A s 41. l J W 4 jWQWW L w P BI 3 WW w WW /4 Filed Aug. 15, 1962 July 7, 1964 P. E. DU BOIS APPARATUS AND METHOD FOR PREVENTING WIND-UP ON ROLLS Filed Aug. 15, 1962 2 Sheets-Sheet 2 2 IN V EN TOR. PAUL E. 1) B 015 PM M' ATTORNEYS United States Patent 3,139,815 APPARATUS AND METHOD FUR PREVENTING WIND-UP 0N RQLLS Paul E. Du Bois, Central St., Eucksport, Maine Filed Aug. 15, 1962, Ser. No. 217,067 13 Claims. (Cl. 100-39) This invention relates to calender stacks and especially to an apparatus and method for preventing wind-up on the calender rolls as a result of a break in the web of paper.

In some types of paper calenders the paper web merely passes around each successive roll and through each successive nip usually from top to bottom with no laterally extending stretches to auxiliary rolls.

However, this invention is directed to the type of calender, sometimes termed a supercalender, which may be twenty to forty feet in height and width, each calender roll of the stack being journalled in massive standards and the web passing from each nip laterally to loop around an auxiliary roll and then to return into the next successive nip.

The calender rolls of such a supercalender may be twenty or more feet in length, one or more feet in diameter and usually have an especially smooth surface so that replacement may cost from two to six thousand dollars each. The paper web is often so fragile that a light blow from the hand will instantly break it. At present such a break can prove most expensive for the reason that the web is travelling at high speed, such as twenty-two hundred feet per minute, and a break among the rolls of the supercalender causes the broken end to wind-up around one of the pressurized nip rolls to ruin the same. Not only is replacement of the roll costly, but the down time of the machine and loss of production all tend to make such a web break and wind-up a serious calamity.

The principal object of this invention is to provide an apparatus and method for preventing wind-up on the nip rolls of a supercalender regardless of where the break takes place along the path of the web.

Another object of the invention is to provide web break sensing means in advance of each nip of a supercalender stack, web severing and deflecting means, at the sensing locations also in advance of each such nip and means for instantly actuating all of the last mentioned means in response to the sensing of a break.

A further object of the invention is to provide a unitary framework rigidly supporting guillotine-type cutter bars, each poised above a laterally extending web stretch just in advance of a calender roll nip, the entire framework being movable downwardly as a unit to sever each stretch and deflect the severed ends away from the entrance of the Still another object of the invention is to provide apparatus, at each of a plurality of break sensing locations, for simultaneously severing and deflecting every stretch of a continuous paper web, just in advance of the entrance of every nip of a calender stack, for releasing the nip pressure and for stopping the rotation of the calender rolls, thereby preventing damage to the calender rolls upon the sensing of a break.

ther objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which:

FIG. 1 is a perspective view of a supercalender with the apparatus of the invention incorporated therein.

FIG. 2 is an enlarged, diagrammatic side elevation of the device shown in FIG. 1 in section on line 2-2 of FIG. 6.

FIG. 3 is a fragmentary perspective view of one set of the rolls shown in FIG. 3.

FIG. 4 is a veiw similar to FIG. 3 showing another embodiment of the web severing and deflecting member of the invention.

FIG. 5 is a view similar to FIG. 4 showing still another embodiment.

FIG. 6 is a front elevation, of the apparatus shown in FIG. 2, and also includes a circuit diagram.

The supercalender 20, illustrated in FIG. 1 is of a well known type, made by Appleton Machine Company of Appleton, Wisconsin, and the figure of an operative 21 is included to show the tremendous size of such a machine. A pair of massive standards 22 and 23 contain a vertical stack 24 of calender rolls, such as 25, 26 and 27, the rolls being over twenty feet in length and smooth surfaced to provide the desired calendering treatment to the continuous paper web 28. A superstructure 29 of walkways and ladders is necessary to permit the operatives to thread the web 28 through the calender roll nips such as 31, 32 and 33 and around the laterally disposed front stack 34 of auxiliary rolls 35, 36 and 37 and around the rear stack 38 of auxiliary rolls 39, 40 and 41. g

The machine 20 includes pressure mechanism 43 for applying the desired nip pressure to the calender rolls of stack 24 and drive mechanism 44 for driving the nip rolls at selected speeds, there being a control circuit 45 for releasing nip pressure and a control circuit 46 for stopping the roll drive mechanism.

As best shown in FIGURE 2, the paper web 28 first enters the stack 24, from the front, in a laterally extending, unsupported stretch 50 to pass around the rear face of the top roll and then into the nip of the two upper rolls. The web 28 then passes in successive, laterally extending, unsupported stretches 51, 52, 53, 54, 55, 56, 57 and 58, with loops around the auxiliary rolls and then back through successive calender roll nips, until it emerges in the final stretch 59 leading away from the machine. A plurality of guide rolls such as 60 are usually provided in the upper part of the machine 20 to control the tension of the web.

The wind-up prevention means 61, of the invention, includes web severing and deflecting means 62, associated with each of the laterally extending stretches of the web 28, break sensing means 63 associated with each such stretch at the severing and deflecting locations and actuation means 64, responsive to the sensing means to instantaneously and simultaneously apply the severing and deflecting means in unison.

The web severing and deflecting means preferably is in the form of a unitary framework 65, comprising an end frame 66 and 67 each at an opposite end of the stack 24 and substantially coextensive in height with the stack.

Each frame includes a front rail 68 and a parallel rear rail 69, detachably joined by the upper and lower rails 7 0 and 71 and formed of rigid material such as metal.

Each lower rail 71 carries a piston 73 vertically movable in a fluid actuated cylinder 74, supported at about floor level, whereby the application of fluid pressure in the conduit 75 will raise both end frames an equal amount into normal, poised position ready to drop when triggered. A foot pedal and leverage system could be used to raise the framework 61 but I prefer power operation from the usual mill air supply controlled by the button, or valve 76, of a conventional type.

Each upper rail 70 carries a central piston 78, slidable in a cylinder 79, the piston 78 compressing a coil spring 80 within the cylinder when the framework is in normal, raised position. A solenoid operated trigger, or latch, 81 is provided at each end of the machine 20, to normally hold the framework 65 in its poised, spring-loaded condition but to instantaneously release the framework to move downwardly when the solenoids are energized.

The web severing and deflecting means 62 is preferably in the form of a plurality of individual, transversely ex tending, members such as 83, 84 and 35 of rigid material, each integrally connected at each opposite end to one of the rails 68 or 69 of the frames 66 and 67 to form a single unit with the framework 65. Each member such as 83 includes a lower cutting edge 87 and at least one vertical face 88 extending upwardly therefrom to bar the advance of an end severed by the cutting edge when the member has been dropped into its lower position.

It will be understood that while flexible cutting tapes, flame, or air. jet, cutters, narrow cutting bars and vertical tine devices might be used to sever the web 28, mere severance may not accomplish the object of the invention which is to prevent wind-up on the calender rolls. A severed end entering one of the pressure nips of the calender roll stack will wrap itself around a roll and ruin the roll. Thus the means 62 of this invention must include, or be associated with, some type of mask, baffie or deflector which bars the advance of a severed end into the nip.

As best shown in FIG. 3, the preferred embodiment of a member such as 83, 84 and 85 is thus a hollow, guillotine-type, metal cutter bar, or blade, co-extensive in length with the calender rolls and at least three inches in height although preferably about eight inches in height. Member 85 is rigid enough and self supporting enough to join the end frames 66 and 67 into a single unit but a slight sag in the middle will give a slicing out which is desirable. The vertical face 88 is full length and full height in this embodiment to serve as a complete bar to a severed end of web 28 even if the end is in strips or tatters.

The sensing means 63 could be of the photo cell type but it is preferred that it be of the pressure actuated Microswitch type and mounted at spaced transverse distances along the lower edge 87 of each member such as 83, 84 and 85. Such switches are designated 90, 91 and 92 and each is arranged to ride on the upper face of the web with the web contacting lever 94 keeping the actuation circuit 95 open while the web is intact. Upon a break in the web 28, in advance of any of the calender roll nips and at any transverse location on the web, the particular switch afiected ceases to be restrained by the web and instantaneously moves to close the actuation circuit 95.

Actuation circuit 95 includesa suitable source of current 96, all of the switches 90, 91 and 92 in parallel and the solenoids 81 which trigger the release of the unitary framework 65. Thus the solenoids are energized, the framework is spring pressed downwardly and all of the laterally extending stretches 50 to 59 are severed as well as deflected away from the nips.

Preferably the circuit 95 includes a suitable relay 120 to actuate the roll pressure release circuit 45 and a similar relay 97 to actuate the roll drive circuit 4-6 whereby the rolls are slowed down and pressure released simultaneously with the sensing of a break.

As shown in FIG. 3, when the vertical face 88 is a full width, full height imperforate barrier, it is preferredv to include an identical cut-out 99 proximate the same end of each member and about three inches in depth. The cut-out'facilitates the threading of the narrow lead strip of a web 28, after a break has occurred and when the calender is being readied for operation. Thus the mem bers such as 83, 84 and 85 when in poised upward position can reach nearly up to the level of the next higher nip but the operative can use the cut-out to grasp the oncoming lead strip and strip it from traveling around the roll.

Another embodiment of the web severing and deflecting means of the invention is shown in FIGURE 4 wherein a transversely extending, skeletonized bafile 101 is illustrated. The baflle 101 may be made of rigid rod material and the lower edge 102 will sever the web, by weight alone, although a sawtooth, or serrated, edge is preferable. The transversely spaced upstanding bars 103, 104 and 4 185, 106 and 107 are the substantial equivalent of the face 88 in barring the advance of the severed end of a web.

Still another embodiment of the web severing and deflecting means of the invention is shown in FIGURE 5 wherein a plurality of rigid elements such as 110, serve to connect the end frames 66 and 67 into a unitary framework. A relatively thin cutting knife 111 having a serrated edge 112, is firmly secured along the lower edge portion of each element 110 by bolts 113 so that it may be removed for sharpening. A plurality of spaced upstanding rods such as 114 are attached to the upper portion of the element 110 to constitute a vertical barrier similar to the face 88.

In operation, the framework 65 is raised by fluid pressure in cylinder 74 to its normal upper position, spring loaded to descend when the solenoid triggers 81 are energized. The super calender 20 is then threaded in the usual manner with the rolls rotating slowly and the lead-in strip manually passed around the various rolls and through the nips.

Upon start-up of the machine, the contact levers 94 are in rubbing engagement with the web, at spaced transverse locations thereacross, in each critical laterally extending unsupported stretch which feeds into a nip. The appropriate contact lever 94, will sense a break and close the actuation circuit 95 instantly, thereby springing the framework 65 downwardly as a unit. The members such as 83, 84 and 85 will each not only sever the stretch with which they are associated, but will form a. gate in front of their respective nips to prevent entrance of the severed end to wind-up on the rolls.

I claim:

1. The method of preventing wind-up on the nip-forming rolls of a calender stack having auxiliary rolls and having unsupported, laterally extending web stretches looped around said rolls, said method comprising the steps automatically sensing a break occurring at any one of a plurality of spaced transverse locations extending across each one of said laterally extending stretches, just in advance of the nip into which said stretch feeds,

then substantially, instantaneously severing each of said stretches, at the break sensing locations thereon simultaneously, and

then deflecting the severed end of each said stretch away from the entrance of the nip into which said stretch normally feeds.

2. In a paper calender of the type having a vertical stack of calender rolls with laterally disposed auxiliary rolls for guiding a continuous paper web through successive calender roll nips and along laterally extending, unsupported stretches to loop around successive auxiliary rolls the combination of wind-up prevention means comprising a plurality of individual web severing and web deflecting members, one for each said stretch, each member extending transversely from one end to the opposite end of said calender at a location adjacent one of said laterally extending, unsupported stretches, just in ad- Vance of one of said calender roll nips;

a plurality of sensing means, each disposed at one of said locations adjacent one of said stretches for sensing a break in said stretch and mechanism actuated by any one of said sensing means for applying said web severing and web deflecting members in unison to simultaneously sever all of said stretches while deflecting the severed ends away from said calender roll nips.

3. A combination as specified in claim 2 wherein said wind-up prevention means is a single unit formed by a pair of vertically disposed end frames, each at an opposite end of said stack, rigidly connected by a front and rear stack of said members, said members being rigid cutter bars of substantial height normally poised above said stretches but movable downwardly to bar the entrance of a nip.

4. A combination as specified in claim 2 wherein each said web severing and Web deflecting member includes a transversely extending cutting edge, substantially coextensive with the width of, and at a spaced distance above, the adjacent stretch of said web and a transversely extending, vertically disposed deflector, substantially co-extensive with the width of, and extending above said cutting edge, said deflector being arranged to intercept an advancing end of said stretch, severed by said edge, to prevent said end from continuing on into a calender roll mp.

5. A combination as specified in claim 2 wherein each said web severing and web deflecting member is a guillotine-type knife poised above said stretch and each said knife includes an identical cut-out in the upper edge thereof, at the same distance from one end of said calender, to facilitate rethreading of a narrow lead strip in said nips.

6. A combination as specified in claim 2 wherein said web severing and Web deflecting members are guillotinetype knives;

said sensing means comprises a plurality of electric switches, spaced along each knife and held open by contact with said web;

and said actuating mechanism comprises an electric circuit including all of said switches, a source of current and solenoid means for releasing all of said knives simultaneously. 1

7. A combination as specified in claim 2 wherein said wind-up prevention means is an integral, rigid unit of predetermined weight with each of said members poised at a spaced distance above their respective stretches, and said unit being movable downwardly by its own weight to position said members in the path of said stretches said unit is spring loaded to move downwardly for severing and deflecting said stretches, and

said actuating mechanism includes a trigger, responsive to said sensing means, for releasing said spring loaded unit.

8. A combination as specified in claim 2 plus power operated means, at each opposite end of said calender operable from one end thereof for moving all of said members, in unison, back to their respective positions adjacent their respective stretches after each actuation of said wind-up prevention means.

9. In a paper calender of the type having a plurality of calender roll nips and a plurality of laterally disposed auxiliary rolls, the paper web forming a plurality of laterally extending stretches, each leading from an auxiliary roll into one of said nips, the combination of web severing and deflecting means including a member extending transversely across each said stretch and located just in advance of the nip into which said stretch feeds, means mounted proximate each said member, and operable transversely across each said stretch for sensing a break in any one of said stretches, and

means, responsive to said sensing means, for simul taneously and instantaneously applying all of said web severing and deflecting means whereby all of said stretches are severed and deflected away from said nips before a broken end can windup on one of said calender rolls.

10. A combination as specified in claim 9 wherein said web severing and deflecting means comprises a unitary framework supporting a plurality of guillotine type members, each having a face of predetermined height, substantially co-extensive in length with said calender rolls and poised above one of said stretches, said framework being normally in upward position but spring loaded toward a downward position with said faces in, and across, the path of said stretches.

11. A combination as specified in claim 9 plus means, responsive to said sensing means, for instantaneously actuating the roll pressure release mechanism of said calender.

12. In a super calender the improvement comprising:

means for severing the Web just in advance of each entering nip;

means for deflecting the so severed web away from each entering nip, and

means including break-sensing means mounted just in advance of each entering nip, proximate said severing and deflecting means, and operable across the web for sensing a break therein and actuating said severing and deflecting means for preventing a broken web from reaching said entering nips.

13. In a supercalender, the combination. of web break sensing means, each operable at spaced points across one of the nip-entering stretches of the web, in advance of each nip of the calender rolls; web severing and deflecting means, including a plurality of members, each extending across each said stretch proximate one of said sensing means, in advance of each said nip and means, responsive to each said first mentioned means, for instantaneously and simultaneously applying all of said last mentioned means 1n llIllSOIl.

References Cited in the file of this patent UNITED STATES PATENTS 

1. THE METHOD OF PREVENTING WIND-UP ON THE NIP-FORMING ROLLS OF A CALENDER STACK HAVING AUXILIARY ROLLS AND HAVING UNSUPPORTED, LATERALLY EXTENDING WEB STRETCHES LOOPED AROUND SAID ROLLS, SAID METHOD COMPRISING THE STEPS OF AUTOMATICALLY SENSING A BREAK OCCURRING AT ANY ONE OF A PLURALITY OF SPACED TRANSVERSE LOCATIONS EXTENDING ACROSS EACH ONE OF SAID LATERALLY EXTENDING STRETCHES, JUST IN ADVANCE OF THE NIP INTO WHICH SAID STRETCH FEEDS, THEN SUBSTANTIALLY, INSTANTANEOUSLY SEVERING EACH OF SAID STRETCHES, AT THE BREAK SENSING LOCATIONS THEREON SIMULTANEOUSLY, AND THEN DEFLECTING THE SEVERED END OF EACH SAID STRETCH AWAY FROM THE ENTRANCE OF THE NIP INTO WHICH SAID STRETCH NORMALLY FEEDS. 